If you want to test the site (which I assume means you want others to view it), you need a webserver so it can be accessed over the internet. If you intend to use scripting language, like php or sql, you need a webserver to interpret it.

Not sure I understand what you are asking here, you would just double click the html file linked to the css so it loads in your browser. In other words, if you just need to test what the css looks like you just open the file and see what it looks like, the same way you would test how a jpeg looks like on the hard drive.

You can edit the CSS in any text editor and as long as the pages are just HTML, CSS, and javascript it will all run in a browser just from your local file system. That means you won’t need anything additional like a local web server.

If the site uses a server side language, like PHP or Ruby, then you would need a local web server to test. It can just “live” on your computer and recommendations as to the best way to get there would vary based on what language and what operating system you’re using.

The easiest thing might just be to type “how to set up a local <language> web server <operating system>” into google and there are usually handy step by step guides to walk you through.

@Qingu – Did you figure it out? Are you using a program like Dreamweaver, or coding by hand? Windows or Mac? Back in the day, you could just drag a HTML file right into an open window with Internet Explorer on Windows. Little more info, and I can definitely help you out.

I’m coding by hand… and I figured out enough to know that it’s actually not CSS that needs fixing, it’s javascript (I think) converting XML into crappy-looking HTML. So that’s a whole other rabbit hole…

If the javascript you’re seeing doesn’t look like “normal” javascript, it’s probably a library. jQuery is probably the most popular, but there’s MooTools, Prototype and a ton of others.

If it is ajax, then that XML is being generated on the back end by another language, so there’s another to learn.

The best advice I could give would be to grab firefox and firebug, which has saved me so much time I should probably send the team Christmas cards. There are other similar tools, but I think this one is still the best. It will let you see exactly what’s being dropped into your page, what styles are applied to individual elements, and the raw communication that goes back and forth between the page and returned XML. Oh, and it’s free.